Download 13 noxious weeds

Table of Contents
Introduction
pg. 2
Management Plans
pg. 3
Species Information
pg. 4-16
Cypress spurge
Diffuse knapweed
Meadow knapweed
Myrtle spurge
Orange hawkweed
Purple loosestrife
Russian knapweed
Spotted knapweed
Dalmatian toadflax
Houndstongue
Leafy spurge
Whitetop
Yellow toadflax
Glossary
pg. 4
pg. 5
pg. 6
pg. 7
pg 8
pg. 9
pg. 10
pg. 11
pg. 12
pg. 13
pg. 14
pg. 15
pg. 16
pg. 17
Appendix
Herbicide Purchasing Guide
Mixing Directions for Small Sprayers
Sprayer Calibrations- Backpack
Sprayer Calibrations- Boom Type Sprayers
Contact Information
NOTE: Species listed in RED fall under the eradication management plan
Introduction
The state of Colorado mandates that each county maintain
control of all noxious weeds within county boundaries. The Routt
County Weed Program uses chemical and biological methods to
manage, control, and eradicate noxious weeds.
Identifying weeds is the primary step in control. Until the
family of the specimen is determined a weed management plan
cannot
accurately,
nor
successfully,
be
developed
and/or
implemented. Noxious weed control is an ongoing battle.
Chemical control methods change while the weeds can become
resistant to chemicals. Consistency is the best method for long-term
and successful eradication of noxious weeds. While noxious weeds
must be eradicated, a certain level of knowledge is required before
any eradication effort should be made.
Thirteen noxious weeds have been identified and placed on
Routt County’s Noxious Weed List, all of which are included in this
booklet. The information sheets on individual species include tips
on identification, different methods of control, recommended
herbicides, and impacts the species have on surrounding habitats.
2
Management Plans
Routt County maintains two different levels of weed control:
1. Eradication
These MUST be destroyed!
7 of the 13 noxious weeds in Routt County fall into this
category.
Treated chemically, but may also be controlled mechanically.
Biological controls are not an option (these species are denoted
in red throughout this booklet.)
2. Suppression or management
The remaining six plants in this booklet fall under this
category.
Chemical management is the primary method of control;
however, biological controls (weevils and other insects) are also
used.
Sometimes the two methods are used together.
3
Cypress Spurge
CHARACTERISTICS
Cypress spurge is a perennial plant that
reproduces by lateral root buds and seeds
Flowers are yellowish-green when plant is
young, and becomes reddish green as plant
matures
Cypress spurge prefers direct sunlight and
occurs mostly in dry to moderately moist
habitats
Soil seed reserve for Cypress spurge is thought
to be at least 8 years
WHY BE CONCERNED?
(Euphorbia Cyparissias)
CAUTION: Cypress spurge plants have a milky
sap that may cause dermatitis or skin rashes
WARNING: Animals should not be pastured
where spurge plants grow
MANAGEMENT
Practice prevention! This is the best way to avoid a spurge infestation.
Clean equipment that has been used in infested areas.
Remove seedlings when young - newly established plants can usually be pulled
without leaving root fragments in the ground.
Re-plant disturbed areas with desirable grasses as soon as possible.
Dispose of weeds properly; bag or burn seed heads or fragments that may
resprout.
Monitor the site for several years, promptly removing new seedlings.
HAND PULLING is not recommended as a way to remove Cypress Spurge due to the
extensive root system and the potentially harmful sap.
MOWING is also not recommended due to the length of the seed reserve.
BIOLOGICAL CONTROLS are not currently available.
HERBICIDES are effective to control Cypress spurge, but should always be applied
with care. Read and follow all labeled instructions. Trade names are used here to
simplify matters - no endorsement is implied. Other brand names may be available
with similar ingredients that also will work. See the label for proper rates, sites and
grazing restrictions.
Paramount can be applied at the flowering stage.
2,4-D + dicamba may also be applied at the flowering stage.
RE-SEEDING can be very helpful in the long-term. After treating an area with
herbicide, re-seed with a grass seed mix in the fall.
4
Diffuse knapweed
CHARACTERISTICS
Flowers are usually white, sometimes purple, and
bloom July through August
WHY BE CONCERNED?
Diffuse knapweed is a non-native species in the
state of CO
Diffuse knapweed is a biennial forb that only
reproduces by seed
Preventing seed production is the key to
management
Diffuse knapweed tends to invade disturbed,
overgrazed areas
(Centaurea diffusa)
MANAGEMENT
PREVENTION is critical!
Practice good pasture management; avoid overgrazing, irrigate and fertilize as needed,
and reseed bare ground. A healthy pasture will help resist weed invasion.
Use weed-free hay and seed and avoid bringing in weed-contaminated soil.
Clean equipment that has been used in infested areas.
Remove seedlings when young - newly established plants can usually be pulled without
leaving root fragments in the ground.
Re-plant disturbed areas with desirable grasses as soon as possible.
Dispose of weeds properly; bag or burn seed heads or fragments that may resprout.
Monitor the site for several years, promptly removing new seedlings.
HAND PULLING is recommended as any method of removal which destroys the root
below soil surface will kill the plant
MOWING is recommended when plant is in full bloom. BE SURE that cut plants are
properly disposed of!
BIOLOGICAL CONTROL is not available.
HERBICIDES are effective to control Diffuse Knapweed, but should always be applied
with care. Read and follow all labeled instructions. Trade names are used here to
simplify matters - no endorsement is implied. Other brand names may be available
with similar ingredients that also will work. See the label for proper rates, sites and
grazing restrictions.
Milestone: apply in spring at rosette to early bolt stage or in fall to rosettes.
2, 4-D Amine should be applied in spring or fall to rosettes. Add non-ionic surfactant.
Tordon 22K: apply in spring or fall
RE-SEEDING can be very helpful in the long-term. After treating, re-seed with a grass
seed mix in the fall.
5
Meadow knapweed
CHARACTERISTICS
Meadow knapweed is a perennial and grows from a
woody crown produces flowers that are purple or
pink in color. Leaves grow up to 6 inches long and 1
inch wide
Plants grow between 20 and 40 inches tall and
bloom in late summer and early fall
WHY BE CONCERNED?
Meadow knapweed is not palatable for livestock
Meadow knapweed primarily reproduces by seed
Habitats include moist sites mainly, but also include
roadsides and open forest areas
This plant disturbs wetland habitats by pushing out
native seedlings
(Centaurea pratensis)
MANAGEMENT
PREVENTION is critical!
Practice good pasture management; avoid overgrazing, irrigate and fertilize as
needed, and reseed bare ground. A healthy pasture will help resist weed
invasion.
Use weed-free hay and seed and avoid bringing in weed-contaminated soil.
Clean equipment that has been used in infested areas.
Remove seedlings when young
Re-plant disturbed areas with desirable grasses as soon as possible.
Dispose of weeds properly; bag or burn seed heads or fragments that may
resprout.
Monitor the site for at least ten years after the last adult plants are eliminated
HAND PULLING and or digging is recommended for small infestations.
BIOLOGICAL CONTROLS are not currently available.
HERBICIDES are effective to control Meadow knapweed, but should always be applied
with care. Read and follow all labeled instructions. Trade names are used here to
simplify matters - no endorsement is implied. Other brand names may be available
with similar ingredients that also will work. See the label for proper rates, sites and
grazing restrictions.
Milestone should be applied either in spring during bolting or during the fall
Tordon apply either in spring during bolting to bud growth or during the fall.
RE-SEEDING can be very helpful in the long-term. After treating, re-seed with a grass
seed mix in the fall.
6
Myrtle spurge
CHARACTERISTICS
Myrtle Spurge is a low growing perennial
Flowers appear from March to May
This plant is an escaped ornamental
The plant grows from a taproot and reproduces by
seed. Plants are capable of projecting seeds nearly 15
feet
WHY BE CONCERNED?
(Euphorbia myrsinites)
Myrtle spurge contains a toxic milky sap, which is
poisonous if digested!
Wearing gloves, long sleeves, and eye protection is
recommended when working with or near Myrtle
spurge
MANAGEMENT
PREVENTION is critical!
Practice good pasture management; avoid overgrazing, irrigate and fertilize as
needed, and reseed bare ground. A healthy pasture will help resist weed
invasion.
Use weed-free hay and seed and avoid bringing in weed-contaminated soil.
Clean equipment that has been used in infested areas.
Remove seedlings when young - newly established plants can usually be pulled
without leaving root fragments in the ground.
Re-plant disturbed areas with desirable grasses as soon as possible.
Dispose of weeds properly; bag or burn seed heads or fragments that may resprout.
Monitor the site for several years, promptly removing new seedlings.
HAND PULLING is recommended only if entire root system can be removed.
CAUTION: always wear gloves and eye protection!
BIOLOGICAL CONTROLS are not available in Routt County due to current
management plans.
HERBICIDES are effective to control Myrtle spurge, but should always be applied with
care. Read and follow all labeled instructions. Trade names are used here to
simplify matters - no endorsement is implied. Other brand names may be available
with similar ingredients that also will work. See the label for proper rates, sites and
grazing restrictions.
2,4-D low-vol ester is moderately effective, but may need more than one
application.
Roundup is highly effective, but will harm any surrounding vegetation.
RE-SEEDING can be very helpful in the long-term. After treating, re-seed with a grass
seed mix in the fall.
7
Orange hawkweed
CHARACTERISTICS
The flowers are orange in color
Leaves are basal; rosette leaves are 4 to 6 inches in
length and have finely toothed margins
This plant contains a milky juice, but it is not
considered an irritant
Orange hawkweed grows in temperate and mountain
regions and can tolerate a variety of conditions.
WHY BE CONCERNED?
Orange hawkweed reproduces from runners, rhizomes,
sporadic root buds, and seed
Orange hawkweed easily escapes gardens and can
readily infest lawns and other garden settings
(Hieracium aurantiacum)
MANAGEMENT
PREVENTION is critical!
Maintain a specific garden or yard area and ensure that this species does not
escape from the confined area.
Clean equipment that has been used in infested areas.
Remove seedlings when young - newly established plants can usually be pulled
without leaving root fragments in the ground.
Re-plant disturbed areas with desirable grasses as soon as possible.
Dispose of weeds properly; bag or burn seed heads or fragments that may
resprout.
Monitor the site for several years, promptly removing new seedlings.
HAND PULLING is not recommended.
BIOLOGICAL CONTROLS are not currently available.
HERBICIDES are effective to control Orange hawkweed, but should always be applied
with care. Read and follow all labeled instructions. Trade names are used here to
simplify matters - no endorsement is implied. Other brand names may be available
with similar ingredients that also will work. See the label for proper rates, sites and
grazing restrictions.
Milestone: Apply when plants are in rosette to bolting stage.
Clopyralid: can be used alone or 2-4-D can be added to it. Either way, it should be
applied when plants are in the rosette growth stage. 2-4-D can also be used alone.
8
Purple loosestrife
CHARACTERISTICS
Flowers bloom from late June through September
and are reddish-purple in color
The stems can grow between 2 and 8 feet tall
WHY BE CONCERNED?
Purple loosestrife is a non-native species in the state
of CO
Purple loosestrife reproduces primarily by seed and
the seeds can be viable in soil between 5 and 20
years
(Lythrum salicaria)
MANAGEMENT
PREVENTION is critical!
Practice good pasture management; avoid overgrazing, irrigate and fertilize as needed,
and reseed bare ground. A healthy pasture will help resist weed invasion.
Use weed-free hay and seed and avoid bringing in weed-contaminated soil.
Clean equipment that has been used in infested areas.
Remove seedlings when young - newly established plants can usually be pulled without
leaving root fragments in the ground.
Re-plant disturbed areas with desirable grasses as soon as possible.
Dispose of weeds properly; bag or burn seed heads or fragments that may resprout.
Monitor the site for several years, promptly removing new seedlings.
HAND PULLING is recommended only for small infestations and should be
performed before seed set.
BIOLOGICAL CONTROLS are not currently available.
HERBICIDES are effective to control Purple loosestrife, but should always be applied
with care. Read and follow all labeled instructions. Trade names are used here to
simplify matters - no endorsement is implied. Other brand names may be available
with similar ingredients that also will work. See the label for proper rates, sites and
grazing restrictions.
Garlon 3A can be applied in summer. If plants are flowering, remove flower heads
before applying herbicide.
Rodeo should be applied in summer. Add a non-ionic surfactant. Again, dispose of
flower heads before applying herbicide.
Aquatice 2, 4-D Amine can be applied in early spring. Only prevents seed
formation. Retreatment is necessary.
RE-SEEDING can be very helpful in the long-term. After treating, re-seed with a grass
seed mix in the fall.
9
Russian knapweed
CHARACTERISTICS
Roots are black in color with a scaly appearance,
flowers are purple in color and are solitary at tips of
upper branches
Russian knapweed can grow to be 3 ft tall
This weed may be toxic to horses and can result in the
animals injury or death
WHY BE CONCERNED?
Russian knapweed is a non-native species in CO
Spreads by roots and seeds
Russian knapweed displaces native vegetation
especially in rangeland and pastures
May occur along roadsides, ditch banks, riparian
zones, pastures, irrigated cropland, clear cuts, and
cropland
(Acroptilon repens)
MANAGEMENT
PREVENTION is critical!
Maintain healthy pastures and rangeland
Use weed-free hay and seed and avoid bringing in weed-contaminated soil.
Clean equipment that has been used in infested areas.
Remove seedlings when young - newly established plants can usually be pulled without
leaving root fragments in the ground.
Re-plant disturbed areas with desirable grasses as soon as possible.
Dispose of weeds properly; bag or burn seed heads or fragments that may resprout.
Monitor the site for several years, promptly removing new seedlings.
MOWING several times before the plants bolt stresses Russian knapweed and forces
them to use nutrient reserves stored in the root system. Mowing needs to be repeated
during the summer, followed by an herbicide application in the fall.
BIOLOGICAL CONTROLS are currently limited a potential insect currently under
investigation. The insect is a gall forming nematode, Subanguina picridis.
HERBICIDES are effective to control Russian knapweed, but should always be applied
with care. Read and follow all labeled instructions. Trade names are used here to
simplify matters - no endorsement is implied. Other brand names may be available
with similar ingredients that also will work. See the label for proper rates, sites and
grazing restrictions.
Milestone can be applied in the spring and summer to plants in the bud and
flowering stage
Tordon 22K should be applied during the same time of year as the Milestone
Telar can be applied in the spring from pre-bloom to bloom and to fall rosettes.
RE-SEEDING can be very helpful in the long-term. After treating, re-seed with a grass
seed mix in the fall.
10
Spotted knapweed
CHARACTERISTICS
Flowers are pink to purple in color and bloom from
June thru October
Grows up to 4 ft tall with erect stems
Seed set usually occurs in mid-August
Spotted knapweed is extremely adaptive
WHY BE CONCERNED?
Spotted knapweed is a short lived perennial forb
that reproduces only by seed. One plant can
produce 40,000 seeds
*This type of knapweed can be distinguished from other
types of knapweeds by the black-tipped bracts (phyllaries)
at the base of the flower
(Centaurea maculosa)
MANAGEMENT
PREVENTION is critical!
Practice good pasture management; avoid overgrazing, irrigate and fertilize as needed,
and reseed bare ground. A healthy pasture will help resist weed invasion.
Use weed-free hay and seed and avoid bringing in weed-contaminated soil.
Clean equipment that has been used in infested areas.
Remove seedlings when young - newly established plants can usually be pulled without
leaving root fragments in the ground.
Re-plant disturbed areas with desirable grasses as soon as possible.
Dispose of weeds properly; bag or burn seed heads or fragments that may resprout.
Monitor the site for several years, promptly removing new seedlings.
BIOLOGICAL CONTROLS are not available in Routt County due to current
management plans.
HERBICIDES are effective to control spotted knapweed, but should always be applied
with care. Read and follow all labeled instructions. Trade names are used here to
simplify matters - no endorsement is implied. Other brand names may be available
with similar ingredients that also will work. See the label for proper rates, sites and
grazing restrictions.
Milestone: spring at rosette to early bolt stage and/or in the fall to rosettes
Curtail: apply in the spring and fall to rosettes
Tordon 22K: apply in spring to rosettes through mid-bolt and in fall to rosettes. Do
NOT apply near trees/shrubs/high water table.
11
DalmatiAn toadflax
CHARACTERISTICS
The plant can grow up to 3 feet tall and has bright
yellow flowers which resemble snapdragons.
The leaves alternate and have a waxy surface
Flowers usually bloom in July
WHY BE CONCERNED?
Dalmatian toadflax is a non-native species to the state
of CO
An individual plant can produce up to 500,000 seeds
Prevention is the key to controlling Dalmatian toadflax
Dalmatian toadflax is highly aggressive and can easily
push out native species
(Linaria dalmatica)
MANAGEMENT
Practice good pasture management; avoid overgrazing, irrigate and fertilize as needed,
and reseed bare ground. A healthy pasture will help resist weed invasion.
Use weed-free hay and seed and avoid bringing in weed-contaminated soil.
Clean equipment that has been used in infested areas.
Remove seedlings when young - newly established plants can usually be pulled without
leaving root fragments in the ground.
Re-plant disturbed areas with desirable grasses as soon as possible.
Dispose of weeds properly; bag or burn seed heads or fragments that may resprout.
Monitor the site for several years, promptly removing new seedlings.
HAND PULLING is recommended only for small infestations. Be sure the entire root is pulled!
MOWING will slow, but not stop, the spread of Dalmatian toadflax. Be careful to mow before
the plant goes to seed in order to maintain control of seed dispersal.
BIOLOGICAL CONTROLS are available. Calophasia lunula feeds on the leaves and flowers of
the plant. Other biological controls are available. For more information contact the Routt
County Extension Office at (970) 879-0825 and ask for CJ Mucklow.
HERBICIDES are effective to control Dalmatian toadflax, but should always be applied with
care. Read and follow all labeled instructions. Trade names are used here to simplify
matters - no endorsement is implied. Other brand names may be available with similar
ingredients that also will work. See the label for proper rates, sites and grazing restrictions.
Tordon 22K: Apply when flowering or in the fall
Telar: Apply in spring or fall. Add a non-ionic surfactant.
2, 4-D + Dicamba: Apply during pre-bloom or flowering stage. Retreatment required. Add a
non-ionic surfactant
RE-SEEDING can be very helpful in the long-term. After treating, re-seed with a grass seed
mix in the fall.
12
\
Houndstongue
CHARACTERISTICS
Each flower produces 4-nutlets which turn into
hooked or barbed prickles when mature
Leaves are alternating and hairy
Other common names are: beggar’s lice, dog’s
tongue, common bur, and glove wart
WHY BE CONCERNED?
Houndstongue is toxic to horses.
Houndstongue grows in disturbed habitats such
as roadsides, sand dunes, or open woodlands
Houndstongue grows a long taproot that can
reach up to 1 meter deep
(Cynoglossum officinale L.)
MANAGEMENT
PREVENTION is critical!
Practice good pasture management; avoid overgrazing, irrigate and fertilize as needed,
and reseed bare ground. A healthy pasture will help resist weed invasion.
Use weed-free hay and seed and avoid bringing in weed-contaminated soil.
Clean equipment that has been used in infested areas.
Remove seedlings when young - newly established plants can usually be pulled without
leaving root fragments in the ground.
Re-plant disturbed areas with desirable grasses as soon as possible.
Dispose of weeds properly; bag or burn seed heads or fragments that may resprout.
Monitor the site for several years, promptly removing new seedlings.
HAND PULLING is recommended for small infestations. Make sure to pull entire root!
MOWING will slow, but not stop, the spread of Houndstongue. Plants that are
periodically mowed continue to flower and produce seed on shorter plants, prolonging
the season of growth and flowering.
BIOLOGICAL CONTROLS are not currently available.
HERBICIDES are effective to control Houndstongue, but should always be applied
with care. Read and follow all labeled instructions. Trade names are used here to
simplify matters - no endorsement is implied. Other brand names may be available
with similar ingredients that also will work. See the label for proper rates, sites and
grazing restrictions.
Telar can be applied in early summer or in the fall. Add a surfactant.
2,4-D can also be applied in early summer or in the fall.
Escort can be applied in early summer or in the fall.
RE-SEEDING can be very helpful in the long-term. After treating, re-seed with a grass
seed mix in the fall.
13
Leafy spurge
CHARACTERISTICS
There is a white, milky, sap-like substance
inside the entire plant
Leafy spurge grows from 1-3ft tall with roots that
are up to 30ft deep
Leafy spurge is one of the first plants to emerge
in the spring
WHY BE CONCERNED?
Leafy spurge is non-native, extremely invasive,
and spreads by extensive creeping roots and
seeds
Leafy spurge has adapted to a large variety of
habitats across the state of CO
(Euphorbia esula)
MANAGEMENT
PREVENTION is critical!
Maintain healthy pastures and rangeland
Clean equipment that has been used in infested areas.
Re-plant disturbed areas with desirable grasses as soon as possible.
Dispose of weeds properly; bag or burn seed heads or fragments that may
resprout.
Monitor the site for several years, promptly removing new seedlings.
Create a management plan for the area that incorporates several compatible
control methods
HAND PULLING is not recommended due to the extensive length of the root system.
MOWING will reduce seed production if repeated bi-monthly during the growing
season.
BIOLOGICAL CONTROL can be accomplished either by allowing sheep and/or goats
to graze the impacted area, or through insect grazing. The flea beetles Apthona
nigriscutis, A. lacertosa, and A. cyparissiae, are effective.
HERBICIDES are effective to control Leafy spurge, but should always be applied with
care. Read and follow all labeled instructions. Trade names are used here to
simplify matters - no endorsement is implied. Other brand names may be available
with similar ingredients that will also work. See the label for proper rates, sites and
grazing restrictions.
Tordon 22K: should be applied in the spring, following full-bloom and/or fall.
Tordon + 2, 4-D: apply in the spring or fall
Plateau: apply in the spring only, during bloom to post-bloom stage
14
WHITETOP
CHARACTERISTICS
Whitetop grows up to 2 feet tall and has white flowers
which are tiny and occur only at the ends of the stem.
The upper leaves clasp the stem and leaves have
jagged edges
Plants usually bloom in May and early June.
Seeds are formed in a bladder-like pod
WHY BE CONCERNED?
Whitetop is an aggressive, non-native species that
invades pastures and meadows
Whitetop is unpalatable and displaces grasses and
other more valuable forage plants for wildlife and
livestock
(Cardaria draba)
It reproduces from seeds and root segments.
photo courtesy "Weeds of the West" Western Society of Weed Science
MANAGEMENT
PREVENTION is critical!
Practice good pasture management; avoid overgrazing, irrigate and fertilize as needed,
and reseed bare ground. A healthy pasture will help resist weed invasion.
Use weed-free hay and seed and avoid bringing in weed-contaminated soil.
Clean equipment that has been used in infested areas.
Remove seedlings when young - newly established plants can usually be pulled without
leaving root fragments in the ground.
Re-plant disturbed areas with desirable grasses as soon as possible.
Dispose of weeds properly; bag or burn seed heads or fragments that may resprout.
Monitor the site for several years, promptly removing new seedlings.
HAND PULLING is recommended only for new seedlings.
MOWING will slow, but not stop, the spread of whitetop. Plants that are periodically
mowed continue to flower and produce seed on shorter plants, prolonging the season
of growth and flowering.
BIOLOGICAL CONTROLS are not currently available.
HERBICIDES are effective to control whitetop, but should always be applied with care.
Read and follow all labeled instructions. Trade names are used here to simplify
matters - no endorsement is implied. Other brand names may be available with
similar ingredients that also will work. See the label for proper rates, sites and
grazing restrictions.
Escort
and Telar are very effective on whitetop. Application needs to occur when
sufficient moisture is available in the soil, and a good non-ionic surfactant must be used.
MCPA is moderately effective, but may need more than one application.
Roundup (glyphosate) if used must be applied only to the whitetop. It is non-selective and
will kill other plants, including grasses. You must re-seed after treatment.
RE-SEEDING can be very helpful in the long-term. After treating, re-seed with a grass
seed mix in the fall.
15
Yellow toadflax
CHARACTERISTICS
The leaves of this plant are narrow, linear and 1-2
inches long
Yellow toadflax is known to be mildly poisonous to
livestock
WHY BE CONCERNED?
Yellow toadflax is an escaped ornamental plant that is
native to the Mediterranean region.
Yellow toadflax can inhabit a wide variety of landscapes
(Linaria vulgaris)
MANAGEMENT
PREVENTION is critical!
Practice good pasture management; avoid overgrazing, irrigate and fertilize as needed,
and reseed bare ground. A healthy pasture will help resist weed invasion.
Use weed-free hay and seed and avoid bringing in weed-contaminated soil.
Clean equipment that has been used in infested areas.
Remove seedlings when young - newly established plants can usually be pulled without
leaving root fragments in the ground.
Re-plant disturbed areas with desirable grasses as soon as possible.
Dispose of weeds properly; bag or burn seed heads or fragments that may resprout.
Monitor the site for several years, promptly removing new seedlings.
HAND PULLING is not recommended due to the extended root system of Yellow
toadflax.
MOWING is also not recommended because of the creeping root system.
BIOLOGICAL CONTROL is the Toadflax weevil. For more information contact the
Routt County Weed Program Supervisor at 870-5246
HERBICIDES are effective to control Yellow toadflax, but should always be applied
with care. Read and follow all labeled instructions. Trade names are used here to
simplify matters - no endorsement is implied. Other brand names may be available
with similar ingredients that also will work. See the label for proper rates, sites and
grazing restrictions.
Tordon + 2, 4-D can be effective if applied at the flowering stage (through fall). Retreatment may be necessary.
RE-SEEDING can be very helpful in the long-term. After treating, re-seed with a grass
seed mix in the fall.
16
Glossary
Weed- Any plant growing in an unwanted area
Noxious Weed- An invasive plant which starts growing in a nonnative area
Poisonous Weed- Has the ability to kill, injure or impair some
species of livestock if they eat it (these can be
native plants)
Annual- A plant which completes its’ life cycle in one growing
season
Biennial- A plant which completes its’ life cycle in two growing
seasons
Perennial- A plant which is regularly repeated or renewed for
several years with new growth each growing season
Broadleaf (or Forb) - an herb other than a grass
Mechanical Control- Mowing, pulling, or burning to disrupt the
growth of the plant
Biological Control- The use of insects or other competitive plants
to disrupt the growth of a plant
Chemical Control- The use of herbicides to disrupt the growth of a
plant
Herbicide- A chemical used to kill or control the growth of a plant
Surfactant- Additives used to make a product penetrate a plant
better
Rhizomes- A horizontal underground stem which can send out
both shoots and roots
Runners- (or stolons) are horizontal stems which grow at the soil
surface; they form new plants at the ends or nodes
Translocate- When the herbicide travels from the leaves (site of
entry) to the roots to kill the plan
17
Herbicide Purchasing Guide
Please note: This guide does NOT replace the label. Legally what is stated on the label MUST be followed. You are liable for all uses of a product. If a site is not on the label of the product you
purchase, you cannot legally use that product on that site. Read the label before you purchase, mix, use, store or dispose of a product!
Common Weeds
Some Labeled Sites
Product
Active
Ingredient
Spot Mixing, from label
(based on treating 1000 sq ft- unless noted)
All thistles, whitetop, knapweeds, toadflax (note: can kill trees
and shrubs if it gets on them or if used where their roots
reach.)
pasture, hay, rangeland
Banvel®
whitetop; houndstongue; biennial thistles; suppress Canada
thistle
pasture and rangeland
Cimarron®
many annual weeds; good on biennial thistles, houndstongue;
okay on Canada thistle; fair on whitetop
non-crop areas, turf, grass
pastures, rangeland
Cornbelt
2,4-D amine, 4 lb.®
Weed B Gon
2,4-D amine
4 oz in 3 gallons of water (area not
specified)
many annual weeds; good on biennial thistles, houndstongue;
okay to good on Canada thistle and toadflax; fair to good on
whitetop
non-crop areas, turf, grass
pastures, rangeland
Cornbelt
2,4-D ester, 6 lb. ®
2,4-D ester
2.6 oz in 3 gallons of water (area not
specified)
thistles, knapweeds
rangeland
Curtail®
whitetop; houndstongue; biennial thistles whitetop;
houndstongue; biennial thistles; suppress Canada thistle
industrial and rangeland
Escort XP®
thistles, knapweeds
rangeland & grass pastures
Forefront®
Aminopyralid, 2,4D
thistles, knapweeds
rangeland, permanent
grass pastures, noncropland
Milestone™
Aminopyralid
2 to 4.8 milliliters in 2.5 gallons of water
(4.9 mL = 1 tsp)
many weeds when young, including grasses, thistles, whitetop,
houndstongue, toadflax
pastures, rangeland, turf
(will kill turf grass!)
Round-Up
Original®
Glyphosate
½ to 10% solution, depending on plant
size and site, see label.
thistles, knapweeds
rangeland & grass pastures
Redeem®
Triclopyr,
clopyralid
1/3 to 1 oz in 1 gallon of water
general broadleaf weeds (including whitetop, thistles, toadflax)
turf
Weed B Gon MAX®
MCPA, Triclopyr,
dicamba
2 fl. oz. per gallon of water for each 500
sq. ft.
general broadleaf weeds (including whitetop & thistles)
Pastures, rangeland,
cropland, & turf
Sword
Dicamba
1 to 4½ teaspoons in 3 gallons of water
Metsulfuron Methyl
1 oz in 100 gallons; must use surfactant
(area not specified)
Clopyralid, 2,4-D
3/8 to 1 oz in 1 gallon of water
Metsulfuron Methyl
MCPA
1 gram, approximately equal to ¼ tsp., in
1 gallon of water with surfactant
½ to 1 oz. in 1 gallon of water
3 oz. in 3 or 4 gallons of water
Surfactants = additives used to make a product penetrate a plant better. Soap is not recommended, as it will bind with many herbicides. Common surfactants
include Activator 90® and AdWet 90®. Use rates vary but usually 2 oz. in 3 gallons or ½% will work.
No endorsement of products mentioned is intended nor is criticism implied of products not mentioned. Information current as of 11/15/08
1 Tablespoon (Tbsp) = 3 teaspoons (tsp)
1 fluid oz = 2 Tablespoons.
Mixing Herbicides for Backpack & Small (3 gallon) Sprayers
Some of the most commonly used sprayers are small hand-held pump sprayers
and backpack sprayers.
These units can be extremely effective for some weed infestations, but the
solutions for them must be carefully mixed.
It is very easy to over apply herbicides with these sprayers. The old adage "if a
little is good, a lot is better" does NOT apply!
o Over application can cause undo expense, kill beneficial plants, and make
weed infestations worse by creating bare patches.
Always follow labeled directions - whatever is on the label is legally binding to
you as an herbicide user. These mixing directions do not supersede a label!
o Check the labels to see if this mix is allowable, and check the label to make
sure that the site where you want to use the product is also on the label.
Usually the section of the label that would apply is called "Spot
Applications."
Mixing metsulfuron and chlorsulfuron herbicides, including Escort®, Cimarron® and
Telar®.
1. Add 3 gallons of water to sprayer.
2. Add 1.3 grams (about 1/2 tsp) of product to water (this roughly equals the one
ounce per acre rate.)
3. Stir the mixture or shake the sprayer for about a minute, until it turns cloudy.
4. Add 1 teaspoon of household ammonia. This should make the solution clear.
If it isn't add a few drops more until it clears.
5. Add approximately 2 Tbsp of surfactant (Activator 90®, Adwet 90®, or similar.
Soap or detergents are not recommended - they will often bind with the
herbicide making less of it available.)
6.
Use this mix within 3 days or less. After that it will drastically lose its potency.
BACKPACK – Sprayer Calibration
NO Math Version!
Step 1:
Establish a calibration plot that is exactly:
18.5 feet wide X 18.5 feet long
Step 2:
Spray the calibrated plot uniformly with water, noting the number of seconds required:
Time Required = ______ seconds.
Spray into a bucket for the same number of seconds.
Measure the number of ounces of water in the bucket:
Volume Sprayed = ______ ounces
The number of ounces collected from the bucket is equal to the number of gallons per
acre the sprayer is delivering:
Gallons Per Acre (GPA) = _______
Step 3:
Step 4:
Step 5:
Adding the Correct Amount of Herbicide to the Tank for Liquid Herbicides
Step 6:
Step 7:
Step 8:
Step 9:
Step 10:
Spray
Volume
GPA
10
20
30
40
50
Record sprayer output in gallons per acre (calculated in Step 5).
Output (volume) = _______ GPA
Determine volume of full spray tank.
Tank volume = _______ gallons
From the herbicide label determine amount of herbicide concentrate to apply per acre.
________ Herbicide per Acre (ounces or pints)
Determine the amount of herbicide to add to each gallon based on the chart below.
Calculate the amount of herbicide to add to one backpack tank
_______ Amount of X _______ number of
=
_______ Total amount of
herbicide/gallon
gallons in a tank
herbicide to add to tank
Recommended Herbicide Rate/Acre
8 oz
5½ tsp
2½ tsp
1½ tsp
1¼ tsp
1 tsp
10 oz
2T
1T
2 tsp
1½ tsp
1¼ tsp
12 oz
2½ T
3½ tsp
2½ tsp
2 tsp
1½ tsp
Amount of MSO to
Add to Each Gallon
2 pints
3½ T
10 tsp
2T
4¾ tsp
3¾ tsp
Example: Assume that the calibration of your sprayer (Step 1-5) yields an output of 30 GPA and your sprayer holds 3 gallons. The
PLATEAU® label for leafy spurge control recommends 8 to 12 oz/acre of herbicide plus 2 pints of MSO. You decide to spray 10
oz/acre of PLATEAU. Go to the chart and read across from 30 GPA to the 10 oz column – the amount of herbicide to add per gallon is 2
teaspoons in the chart. Since your sprayer holds 3 gallons of total solution, you would add 6 teaspoons (or 2 Tablespoons) of herbicide to
your tank. Go to the chart and read across from 30 GPA to the 2 pints column – the amount of MSO to add per gallon is 2 Tablespoons.
Add 6 Tablespoons (or 3 fluid ounces) of MSO in addition to the water and herbicide in each tank.
Liquid Conversions:
3 teaspoons = 1 tablespoon
tsp = teaspoon; T = Tablespoon; oz = ounces
8 ounces = 1 cup
2 tablespoons = 1 ounce
1 cup = 16 tablespoons
For calibrating hand wand sprayers (ATV) see: http://www.ext.vt.edu/pubs/forestry/456-502/456-502.html#L.com
Greg Brown
Weed Supervisor
PO Box 773598
136 6th Street, Suite 103
Steamboat Springs, CO 80477
Office: 970-870-5246
Fax: 970-879-3992
Email: [email protected]
CJ Mucklow
Routt County Extension
PO Box 772830
136 6th Street, Suite 101
Steamboat Springs, CO 80477
Office: 970-879-0825
Fax: 970-8705383
Email: [email protected]
Feel free to contact us!
846-2358
Cell: 970-
Fax: 970-870-5383
Email:
[email protected]